I am seeking to understand if search engines treats subdomains as a complete website or as a page of the main domain name. I have a website http://portalshops.com and users get web portals using subdomains eg http://greg.portalshops.com . Would each subdomain be seen a a link of the main domain name or as an independent website linking to portalshops.com? Does subdomains increase ranking in terms of sites linking back to the main domain? Please contribute